This book describes a new control design technique called Coefficient Diagram Method (CDM), whereby practical control engineers without deep control theories and mathematics background can design a good controller for their specific plants. In addition, control experts can solve some complicated design problems. Since the CDM was first introduced in 1998, it reveals from the literature that CDM has provided successful controller designs for a variety of practical control problems. In the last two decades, a great deal of research has been done on CDM, while a growing number of researchers want to learn and utilize the method. However, there has been no textbook to learn it systematically so far. This book is motivated by such a need. It is also suitable as a textbook or reference book for master programs in control engineering.